Airplanes, once a technology wasteland for passengers, now offer Wi-Fi on many flights, especially domestic U.S. trips. How does in-flight Wi-Fi work? Let’s look at the technology involved in offering Wi-Fi in the air.
Some airlines offer Wi-Fi service the same way you get cell service, through ground-based towers. This type of service requires two antennas installed in the belly of the plane that pick-up signals from cell towers. The Air-to-Ground (ATG) system allows passengers to check emails, use Facebook, and other sites, but the service only offered slow speeds early on, not fast enough to stream movies or music. Wi-Fi speeds now range between 9–15 Mbps giving passengers more internet capabilities when they fly.
The fastest Wi-Fi comes from satellites. This service works like a rooftop television dish on your home, picking up waves from a satellite in orbit, except the dish is on top of the plane. The only catch? The plane’s Wi-Fi dish must be directed toward the satellite as it flies. Once connected to the signal, you receive Wi-Fi speeds of up to 40–70 Mbps, depending on the company offering the service. That’s fast enough for streaming video and satellite Wi-Fi even offers coverage when flying over the ocean.
Although some airlines offer free in-flight Wi-Fi, most charge a fee. Planes added extra wiring, antennas, and satellite dishes in order to offer Wi-Fi service to passengers, and these added costs pass on to the traveler. Plus, a satellite dish adds weight and antennas increase drag, which means the plane uses more fuel.
Another cost factor is your smartphone service network. Certain providers, like T-Mobile’s Gogo inflight Wi-Fi, offer a free hour of service on airlines with Gogo service. Most U.S. airlines offer the Gogo service during flights that will work with your T-Mobile connected device. JetBlue Airline offers free Wi-Fi on its flights and a few overseas airlines do too.
Aside from the obvious requirement of antennas or satellite dishes, what else does a plane need for Wi-Fi? Inside the wall panels of a plane, usually on the right side, are black boxes serving as Wi-Fi access points. (These black boxes have nothing to do with the flight recorders in the cockpit.) These boxes function just like a router in your home or office. Each black box connects through special cables offering Wi-Fi throughout the plane.
Of course, this technology comes at a high cost. The black box router on a plane costs up to 10 times what a router in your home costs. Not only that, these routers break often and the plane needs to land before IT personnel come aboard and resolve the issue. So, don’t bother your flight attendant if the Wi-Fi goes down — fixing the internet is not one of their skills. Once the plane lands, a service tech comes on-board to handle the situation.
Rest assured though, a non-functioning internet is an inconvenience but not a reason to delay a flight. Reading is always an option, plus airlines still offer their own in-flight movies and games.
Image via Flickr by Anthony Quintano
Since Wi-Fi covers the entire plane, expect some limitations on data. Airlines use “auto-throttle” to equally distribute data for all passengers. The number of passengers affects the speed of the internet. If only a few passengers use the Wi-Fi then the speed is faster than 50 passengers using the system. Plus, the ATG service uses only front and rear facing antennas, and the satellite systems only connect to one satellite at a time. Many times, in-flight users experience short breaks in service as the airplane switches towers or satellites. Plus, when using cell towers, the service needs areas with good coverage.
When flying over sparsely populated areas or the ocean, ATG does not work. No service works around the north and south poles. So, don’t expect internet service when traveling to Santa’s workshop.
Internet access keeps spreading, and travelers do not need to go without. Most airlines offer some type of Wi-Fi service and in-flight Wi-Fi continues to evolve, so the slow speeds and spotty service should improve in the years to come.